GROWING DEGREE DAY ACCUMULATIONS through June 12th at the NWMHRS

Year       2000     1999     1998     1997
GDD42    978      1102     1066      658
GDD50    505        635       582       329

GROWTH STAGES:
Pear: Bartlett -- 20mm
Apple: Red Delicious -- 18mm
Sweet Cherry: Napoleon -- 16mm
Tart Cherry: Montmorency -- 14mm
Grapes: Chardonnay -- 10"-16" shoots

COMMODITY REPORTS

Tart cherries are currently 354 degree days after full bloom at the NWMHRS, while in Northport they are 270 degree days after full bloom. At this point all tarts should be protected from plum curculio, even the cooler areas should protect for them due to the cooler season and the fact that tree phenology is ahead of the insects. No cherry fruit fly has emerged yet. Black cherry aphids are a problem in some blocks, but are an economic problem only in young trees in most circumstances. Lesser peach tree borers averaged 22/trap. Trunk sprays will still be very beneficial if they haven't been applied yet. Tart cherry yellows is just beginning to express itself in the last few days, with some leaves beginning to drop off. Sweet cherries are starting to take on color, which means that their brown rot susceptibility has increased dramatically. Growers should spray them with full covers on a 10 to 14 day schedule depending on the weather. Bacterial Canker leaf symptoms are plentiful, often times associated with spray injury. The new growth should not have the same problems with the warmer weather being prevalent.

Apple growers should be scouting their young orchards for fireblight strikes. Although it appears we came through the bloom period in good shape, these strikes can spread in the summer storms. Primary apple scab is over for the year. Additional fungicide sprays are only necessary if you are going to have secondary scab (McIntosh) or have problems with sooty blotch/ fly speck. Codling moth averaged 6.6/trap at the NWMHRS, while the abandoned orchard averaged 11/trap. Many blocks have biofixed by this point. If you biofixed on June 1^st then you have accumulated 170 degree days towards the 250 needed before you should spray. June 17^th is the predicted spray date - based on degree totals for the NWMHRS.  Growers who are not trapping should apply an insecticide by this weekend to assure clean fruit. Potato leafhopper pressure has greatly increased, growers should check their plums, young apples and grapes.

Pear psylla summer adults have emerged and some of the hard shell stage still remain behind feeding. Egg laying from the adults has just begun. 

Wild grapes came into bloom last week. Typically the early blooming varieties like Baco will bloom about 7 to 10 days after the wild grapes, with many of the viniferas following those 3 to 7 days later.

MISCELLANEOUS

LORS-BAN
(From Scaffolds, Vol.9, No. 13, June 12, 2000, by Art Agnello, Entomology, Geneva)

On 8 June, as part of the Clinton Administration's goal of reducing the potential exposure of children to all pesticides, the EPA announced an agreement with Dow AgroSciences to severely restrict the use of all products containing the active ingredient chlorpyrifos, sold in the agricultural market as Lorsban. Although Dow stated that the decision would have a "minimal impact on agriculture", the apple industry will take the biggest hit in the effects on its current pest control practices. The agreement restricts the use of Lorsban 4EC and 50WP/WS in apples to pre-bloom applications only, effective 31 Dec. 2000. The EPA also intends to reduce the tolerance for chlorpyrifos residues in apples, which currently stands at 1.5 ppm. Restricted Entry Intervals (REI's) following treatments of Lorsban on some fruit crops will also be extended, although according to Dow, these are not likely to affect current worker practices in most crops. Additionally, Lorsban 4E (and Lorsban 50W packaged in containers smaller than 25 lbs) will become Restricted Use Pesticides, effective 1 Feb. 2001. For more detailed information on the chlorpyrifos risk issues, documentation can be found at: http://www.epa.gov/pesticides/op/chlorpyrifos.htm.
 
 

Please send any comments or suggestions regarding this site to: 
Bill Klein, kleinw@pilot.msu.edu

Last Revised:6-13-00